What does the switch do on the BCreekmur Uglyface vero layout?

[PedalBuilder]

I am referring to the one found here:

http://www.aronnelson.com/gallery/main.php/v/bcreekmur/uglyface_with_mod.jpg.html

I did a search and found some broken links.  I was wondering if someone could fill me in before I attempt it.  Thanks!
Steve

[PedalBuilder]

No guesses?

[soggybag]

Interesting idea, looks to me like the switch turns on the Oscillator and mixes with guitar signal from the 386. One position is Ugly Face. The other is 555 Oscillator plus 386 guitar.

[PedalBuilder]

Do you think it would be appropriate to label it as a blend switch?  I am making this version for a friend and have to etch the box before I can mount everything in it (and thus find out how it sounds).  I thought it was, but it looks like it does a bit more than just turn on the blend function.  My knowledge of the 555 is too limited to tell from the schematic.